Route equirectangular export writes through app core

src/app_core/document_export.h

@@ -52,6 +52,10 @@ struct DocumentDepthExportPayload {
     std::span<const std::byte> depth_bytes;
 };
 
+struct DocumentExportFilePayload {
+    std::span<const std::byte> bytes;
+};
+
 struct DocumentExportCollectionPngPayload {
     std::string path_suffix;
     std::span<const std::byte> bytes;
@@ -231,6 +235,16 @@ public:
     virtual void publish_exported_image(std::string_view path) = 0;
 };
 
+class DocumentExportFileWriteServices {
+public:
+    virtual ~DocumentExportFileWriteServices() = default;
+
+    virtual pp::foundation::Status write_binary_file(
+        std::string_view path,
+        std::span<const std::byte> bytes) = 0;
+    virtual void publish_exported_image(std::string_view path) = 0;
+};
+
 class DocumentExportCollectionWriteServices {
 public:
     virtual ~DocumentExportCollectionWriteServices() = default;
@@ -928,6 +942,27 @@ document_cube_face_export_names() noexcept
     return pp::foundation::Status::success();
 }
 
+[[nodiscard]] inline pp::foundation::Status execute_document_export_file_write(
+    const DocumentExportFileTarget& target,
+    DocumentExportFilePayload payload,
+    DocumentExportFileWriteServices& services)
+{
+    if (target.path.empty()) {
+        return pp::foundation::Status::invalid_argument("export file target requires a path");
+    }
+    if (payload.bytes.empty()) {
+        return pp::foundation::Status::invalid_argument("export file payload must not be empty");
+    }
+
+    const auto write_status = services.write_binary_file(target.path, payload.bytes);
+    if (!write_status.ok()) {
+        return write_status;
+    }
+    services.publish_exported_image(target.path);
+
+    return pp::foundation::Status::success();
+}
+
 [[nodiscard]] inline pp::foundation::Status execute_document_export_collection_write(
     const DocumentExportCollectionTarget& target,
     std::span<const DocumentExportCollectionPngPayload> payloads,